Evidence for the high-energy (collinear) van der Waals isomer of the acetonitrile dimer

C E H  Dessent; J  Kim; M A  Johnson

Evidence for the high-energy (collinear) van der Waals isomer of the acetonitrile dimer

C E H Dessent, J Kim, M A Johnson

Chemistry

Research output: Contribution to journal › Letter › peer-review

Abstract

While the stable configuration of the acetonitrile dimer has antiparallel dipole moments, recent calculations [Popelier, et al. Faraday Discuss. 1994, 97, 243] reveal a high-energy isomer in which the dipoles are collinearly aligned. We report direct evidence for the existence of this isomer using a strategy in which we enforce the less-favorable orientation of the neutrals by electrostatically binding them to the iodide ion in the I-.(CH3CN)(2) cluster. The collinear dimer is then released by photoexcitation of the dipole-bound excited state of I-.(CH3CN)(2), producing the (CH3CN)(2)(-) anion as the dominant ionic photofragment. The fragment is mass selected and stripped of the excess electron in a modest external electric field (similar to 10 kV/cm), indicating that the anion consists of a diffuse electron as expected for a ''dipole-bound'' species. This behavior suggests that the force field of the neutral ''core'' complex supports a minimum in the highly dipolar, collinear configuration.

Original language	English
Pages (from-to)	12-14
Number of pages	3
Journal	Journal of Physical Chemistry A
Volume	100
Issue number	1
Publication status	Published - 4 Jan 1996

Keywords

SPECTROSCOPY

Cite this

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title = "Evidence for the high-energy (collinear) van der Waals isomer of the acetonitrile dimer",

abstract = "While the stable configuration of the acetonitrile dimer has antiparallel dipole moments, recent calculations [Popelier, et al. Faraday Discuss. 1994, 97, 243] reveal a high-energy isomer in which the dipoles are collinearly aligned. We report direct evidence for the existence of this isomer using a strategy in which we enforce the less-favorable orientation of the neutrals by electrostatically binding them to the iodide ion in the I-.(CH3CN)(2) cluster. The collinear dimer is then released by photoexcitation of the dipole-bound excited state of I-.(CH3CN)(2), producing the (CH3CN)(2)(-) anion as the dominant ionic photofragment. The fragment is mass selected and stripped of the excess electron in a modest external electric field (similar to 10 kV/cm), indicating that the anion consists of a diffuse electron as expected for a ''dipole-bound'' species. This behavior suggests that the force field of the neutral ''core'' complex supports a minimum in the highly dipolar, collinear configuration.",

keywords = "SPECTROSCOPY",

author = "Dessent, {C E H} and J Kim and Johnson, {M A}",

year = "1996",

month = jan,

day = "4",

language = "English",

volume = "100",

pages = "12--14",

journal = "Journal of Physical Chemistry A",

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publisher = "American Chemical Society",

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TY - JOUR

T1 - Evidence for the high-energy (collinear) van der Waals isomer of the acetonitrile dimer

AU - Dessent, C E H

AU - Kim, J

AU - Johnson, M A

PY - 1996/1/4

Y1 - 1996/1/4

N2 - While the stable configuration of the acetonitrile dimer has antiparallel dipole moments, recent calculations [Popelier, et al. Faraday Discuss. 1994, 97, 243] reveal a high-energy isomer in which the dipoles are collinearly aligned. We report direct evidence for the existence of this isomer using a strategy in which we enforce the less-favorable orientation of the neutrals by electrostatically binding them to the iodide ion in the I-.(CH3CN)(2) cluster. The collinear dimer is then released by photoexcitation of the dipole-bound excited state of I-.(CH3CN)(2), producing the (CH3CN)(2)(-) anion as the dominant ionic photofragment. The fragment is mass selected and stripped of the excess electron in a modest external electric field (similar to 10 kV/cm), indicating that the anion consists of a diffuse electron as expected for a ''dipole-bound'' species. This behavior suggests that the force field of the neutral ''core'' complex supports a minimum in the highly dipolar, collinear configuration.

AB - While the stable configuration of the acetonitrile dimer has antiparallel dipole moments, recent calculations [Popelier, et al. Faraday Discuss. 1994, 97, 243] reveal a high-energy isomer in which the dipoles are collinearly aligned. We report direct evidence for the existence of this isomer using a strategy in which we enforce the less-favorable orientation of the neutrals by electrostatically binding them to the iodide ion in the I-.(CH3CN)(2) cluster. The collinear dimer is then released by photoexcitation of the dipole-bound excited state of I-.(CH3CN)(2), producing the (CH3CN)(2)(-) anion as the dominant ionic photofragment. The fragment is mass selected and stripped of the excess electron in a modest external electric field (similar to 10 kV/cm), indicating that the anion consists of a diffuse electron as expected for a ''dipole-bound'' species. This behavior suggests that the force field of the neutral ''core'' complex supports a minimum in the highly dipolar, collinear configuration.

KW - SPECTROSCOPY

M3 - Letter

SN - 1089-5639

VL - 100

SP - 12

EP - 14

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

IS - 1

ER -